CHANDRA X-RAY OBSERVATORY · The Operations & Control Center (OCC) is staffed by the CXC, with the Flight Operations Team provided by TRW. The OCC has a glass-walled area outside

CHANDRA X-RAY OBSERVATORY

The Chandra X-ray Observatory is the third in NASA's family of GreatObservatories that includes the Hubble Space Telescope and the ComptonGamma Ray Observatory. NASA's Marshall Space Flight Center manages theChandra program. TRW is the prime contractor for the spacecraft. Keysubcontractors include Ball Aerospace & Technologies, Inc., Eastman KodakCompany, and Raytheon Optical Systems, Inc. The scientific instruments werebuilt by teams from MIT, Pennsylvania State University, the SmithsonianAstrophysical Observatory, the Laboratory for Space Research in theNetherlands, and the Max Planck Institute in Germany. The Smithsonian'sChandra X-ray Center controls science and flight operations from Cambridge,MA.

The Chandra X-ray Observatory & First Light

Table of Contents

I. Press Guide to Chandra Contacts

II. Fact Sheets & BiographiesA. Fact Sheets:

1. Cassiopeia A, CXC2. PKS 0637-752, CXC3. Chandra X-ray Observatory Center, CXC4. Exploring the Invisible Universe, MSFC5. Chandra Quick Facts, MSFC

B. Biographies:1. Dr. Robert Kirshner, Associate Director, Harvard-Smithsonian Center for

Astrophysics2. Dr. Harvey Tananbaum, Director, Chandra X-ray Center3. Dr. Edward J. Weiler, Associate Administrator for Space Science, NASA4. Dr. Martin C. Weisskopf, Project Scientist, Chandra X-ray Observatory

A PRESS GUIDE TO CHANDRA CONTACTS

Dr. Wallace Tucker, Chandra Science Spokesperson.Smithsonian Astrophysical Observatory, Cambridge, MA617.496.7998; FAX: 617.495.7356e-mail: [email protected]

KEY CHANDRA SCIENTISTS:

Dr. Harvey Tananbaum, Director, Chandra X-ray Observatory Center (CXC)Smithsonian Astrophysical Observatory, Cambridge, MA617.495. 7248 FAX: 617.495.7356email: [email protected]

Dr. Claude R. Canizares, Associate Director, Chandra X-ray Observatory CenterPrincipal Investigator, High Energy Transmission GratingCenter for Space ResearchMassachusetts Institute of Technology, Cambridge, MA617.253.7501 FAX: 617.253.3111email: [email protected]

Dr. Martin C. Weisskopf, Chandra Project ScientistChief Scientist for X-Ray AstronomyMarshall Space Flight Center, Huntsville, AL205.544.7740 FAX: 205.544.7754e-mail: [email protected]

Dr. Roger Brissenden, Program Manager, Chandra X-ray Observatory CenterSmithsonian Astrophysical Observatory, Cambridge, MA617 495 7387 FAX: 617.496.7067email: [email protected]

Dr. Gordon Garmire, Principal Investigator, AXAF CCD Imaging Spectrometer (ACIS)Penn State Univ., University Park, PA814. 865.1117 FAX: 814.865.2977email: [email protected]

Dr. Stephen S. Murray, Principal Investigator, High Resolution Camera (HRC)Associate Director, High Energy Astrophysics DivisionSmithsonian Astrophysical Observatory, Cambridge, MA

617.495.7205 FAX: 617.495.7356e-mail: [email protected]

Dr. Albert Brinkman, Principal Investigator, Low Energy Transmission GratingSpace Research Organization of Netherlandse-mail: [email protected]

NASA CONTACTS

Dr. Edward J. Weiler, Associate Administrator for Space Science Code SNASA Headquarters, Washington, DC 20546202.358.1409 FAX: 202.358.3092email: [email protected]

Dr. Alan N. BunnerScience Program Director, Structure and Evolution of the UniverseNASA Headquarters, Washington D.C. 20546Phone 202.358.0364 FAX: 202.358.3096email: [email protected]

Donald Savage, Public Affairs OfficerOffice of Space ScienceNASA Headquarters, Washington D.C.Phone 202.358.1727 FAX: 202.358.3093email: [email protected]

Dave Drachlis, Media Relations OfficeMarshall Space Flight Center, Huntsville, ALPhone 256.544.6538 FAX: 256.881.9302email: [email protected]

Fact Sheet

CASSIOPEIA A

Cassiopeia A (Cas A) is the remnant of a massive star that exploded about 300 yearsago. The X-ray image shows an expanding shell of hot gas produced by the explosion.This gaseous shell is about 10 light years in diameter, and has a temperature of about50 million degrees.

The material from the explosion is rushing outward at supersonic speeds in excess often million miles per hour. As this matter crashes into gas that surrounds the former star,shock waves analogous to awesome sonic booms heat the gas and heat the ejectedmatter.

The Cas A SupernovaA supernova occurs when a massive star has used up its nuclear fuel and the pressuredrops in the central core of the star. The matter in the core is crushed by gravity tohigher and higher densities, and temperatures reach billions of degrees. Under theseextreme conditions, nuclear reactions occur violently and catastrophically reversing thecollapse. A thermonuclear shock wave races through the now expanding stellar debris,fusing lighter elements into heavier ones and producing a brilliant visual outburst.

About every fifty years in our galaxy, a massive star explodes. The shell of matter thrownoff by the supernova creates a bubble of multi-million degree gas called a supernovaremnant. Cas A is a prime example. The hot gas will expand and produce X-rays forthousands of years.

The nature of the explosion that produced Cas A has been an enigma. Although radio,optical and x-ray observations of the remnant indicate that it was a powerful event, thevisual brightness of the outburst was much less than a normal supernova. ApparentlyCas A was produced by the explosion of an unusual massive star that had previouslyejected most of its outer layers.

Probing Cas A Mysteries with NASA's Chandra X-ray ObservatoryChandra's spectacularly vivid images of Cas A allow scientists to trace the dynamics ofthe remnant and its collision with any material ejected by the star before it exploded.Chandra detectors provide scientists with precise x-ray spectra– measurements of theenergies of individual x-rays–from the Cas A remnant. These measurements make itpossible to identify which heavy elements are present and in what quantities. Chandra'sobservations should help astronomers to resolve the long-standing mystery as to thenature and origin of Cas A.

A related mystery is whether the explosion that produced Cas A left behind a neutronstar, black hole, or nothing at all. This "First Light" Chandra image of Cas A shows abright object near the center of the remnant! Longer observations with Chandra candetermine if this is the long sought for neutron star or black hole.

Importance of SupernovaeThe study of remnants of exploded stars, or supernovae, is essential for ourunderstanding of the origin of life on Earth. The cloud of gas and dust that collapsed toform the sun, Earth and other planets was composed mostly of hydrogen and helium,with a small amount of heavier elements such as carbon, nitrogen, oxygen and iron. Theonly place where these and other heavy elements necessary for life are made, is deep inthe interior of a massive star. There they remain until a catastrophic explosion spreadsthem throughout space.

Supernovae are the creative flashes that renew the galaxy. They seed the interstellargas with heavy elements, heat it with the energy of their radiation, stir it up with the forceof their blast waves and cause new stars to form.

Fact Sheet

PKS 0637-752

PKS 0637-72 is so distant that we see it as it was 6 billion years ago. It is a luminousquasar that radiates with the power of 10 trillion suns from a region smaller than oursolar system. The source of this prodigious energy is believed to be a supermassiveblack hole.

Radio observations of PKS 0637-752 show that it has an extended radio jet thatstretches across several hundred thousand light years. Chandra's x-ray image reveals apowerful x-ray jet of similar size that is probably due to a beam of extremely high-energyparticles.

QuasarsQuasars are distant, energetic objects. They are compact intense sources of X-rays aswell as visible light, and can be brighter than hundreds of galaxies put together.

Through an optical telescope quasars look star-like. It wasn't until the 1950's, when radioastronomy was first developed, that astronomers realized these were extra-galacticobjects that were emitting enormous amounts of radio energy. This important discoverycaused them to be named quasars, short for "Quasi-stellar radio sources". Since then,many quasars have been discovered that produce little or no radio emission. They aresometimes called quasi-stellar objects or QSO's, but the name quasars is generally usedto describe both types of objects.

The power of a quasar depends on the mass of its central black hole and the rate atwhich it swallows or accretes matter. Almost all galaxies, including our own, are thoughtto contain a supermassive black hole in their centers. Quasars represent the extremecases where the rate of accretion is so high that the energy output due to the infallingmatter is a thousand times greater than the galaxy itself.

One of the most intriguing features of supermassive black holes is that they do not suckup all the matter that falls within their sphere of influence. Most of the matter fallsinexorably toward the black hole, but some explodes away from the black hole in highenergy jets that move at near the speed of light. Radio observations have revealed thatthese jets are a common feature of quasars.

NASA's Chandra X-ray Observatory Reveals Powerful X-ray Jet in PKS 0637-752The x-ray jet observed for the first time by Chandra in PKS 0637-752, is a dramaticexample of a cosmic jet. It has blasted outward from the quasar into intergalactic spacefor a distance of at least 200,000 light years! The jet's presence means thatelectromagnetic forces are continually accelerating electrons to extremely high energiesover enormous distances. Chandra observations, combined with radio observations,should provide insight into this important cosmic energy conversion process.

ChandraOperations

Control Center

Fact Sheet

THE CHANDRA X-RAY OBSERVATORY CENTER

The Chandra X-Ray Observatory, launchedon July 23, 1999, has taken its place with theHubble Space Telescope and ComptonGamma Ray Observatory in NASA's fleet ofGreatObservatories. As the world's premierX-ray observatory, Chandra givesastronomers a powerful new tool toinvestigate the hot regions of the universewhere black holes, exploding stars, andcolliding galaxies hold sway.

The Chandra X-Ray Observatory CenterThe Chandra program, managed by NASA's Marshall Space Flight Center in Huntsville,Alabama, is an example of NASA's initiative to streamline the operations of its spacescience missions. The Smithsonian Astrophysical Observatory's Chandra X-Ray Center(CXC), under the direction of Dr.Harvey Tananbaum, is located at the Harvard-Smithsonian Center for Astrophysics in Cambridge Massachusetts. The CXC isresponsible for planning the science observations based on proposals from the scientificcommunity, processing data received from the observatory, and providing technical andscientific support to the scientists who use Chandra. The Center operates theobservatory from its Operations & Control facility located at One HampshireStreet in Cambridge, Massachusetts.

The CXC is a collaboration of personnel from the SmithsonianAstrophysical Observatory, the Massachusetts Institute of Technology(MIT), and the Chandra prime contractor, TRW.

The Operations & Control Center (OCC) is staffed by the CXC, with theFlight Operations Team provided by TRW. The OCC has a glass-walled area outside the main control room where visitors and press canwatch the Flight Operations Team and mission specialists as theycommunicate with the observatory and carry out the space flightoperations.

Commands for executing the observationplan are transmitted from the OCC to one ofthree ground stations (in Spain, Australia, orCalifornia) that make up NASA's DeepSpace Network (DSN). The DSN relays thecommands to the orbiting spacecraft. Thespacecraft carries out the commands andpoints the telescope to the specified targets,and moves the science instruments to theirappropriate positions.

During routine operations, science data andmonitoring data will be sent from the spacecraft to the OCC, via the DSN, approximatelyevery eight hours. Scientists and engineers will use monitoring data to assess Chandra'scondition. If the health or safety of the observatory appears to be in danger, theoperating mode and the observation plans will be modified.

Data from Chandra observations are processed at the Chandra Center. Observatorycalibration data will be made public as soon as possible. The scientific data belonging toguest observers and guaranteed time observers can be held by them for one year toallow time for analysis and publication of scientific results. The data are then placed inthe public archive.

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Marshall Space Flight Center Fact Sheet

Exploring The Invisible Universe:The Chandra X-ray Observatory

To the human eye, space appears serene and void. It isneither.

To the "eye" of an X-ray telescope, the universe is totallydifferent – a violent, vibrant, and ever-changing place.Temperatures can reach millions of degrees. Objects areaccelerated by gravity to nearly the speed of light andmagnetic fields more than a trillion times stronger than theEarth’s cause some stars to crack and tremble.

NASA’s newest space telescope, called the ChandraX-ray Observatory, will allow scientists from around theworld to obtain unprecedented X-ray images of these and other exotic environments to helpunderstand the structure and evolution of the universe. The observatory will not only help toprobe these mysteries, but also will serve as a unique tool to study detailed physics in alaboratory that cannot be replicated here on earth – the universe itself. NASA’s Chandra X-rayObservatory has every prospect of rewriting textbooks and helping technology advance in thecoming decade.

The Chandra X-ray Observatory will provide unique and crucial information on the nature ofobjects ranging from comets in our solar system to quasars at the edge of the observableuniverse. The observatory should provide long-sought answers to some major scientificquestions, such as:

What and where is the "Dark Matter" in our universe? The largest and most massiveobjects in the universe are galaxy clusters - enormous collections of galaxies, some likeour own. These galaxies are bound together into a cluster by gravity. Much of their massis in the form of an incredibly hot, X-ray emitting gas that fills the entire space betweenthe galaxies. Yet, neither the mass of the galaxies, nor the mass of the hot X-ray gas isenough to provide the gravity that we know holds the cluster together. X-rayobservations with the Chandra X-ray Observatory will map the location of the dark matterand help us to identify it.

What is the powerhouse driving the explosive activity in many distant galaxies? Thecenters of many distant galaxies are incredible sources of energy and radiation –especially X-rays. Scientists theorize that massive black holes are at the center of theseactive galaxies, gobbling up any material – even a whole star – that passes too close.Detailed studies with the Chandra X-ray Observatory can probe the faintest of theseactive galaxies, and study not only how their energy output changes with time, but alsohow these objects produce their intense energy emissions in the first place.

Since X-rays are absorbed by the Earth’s atmosphere, space-based observatories arenecessary to study these phenomena. To meet this scientific challenge, the Chandra X-rayObservatory, NASA’s most powerful X-ray telescope, was launched in July 1999. Complementingtwo other space observatories now orbiting Earth – the Hubble Space Telescope and theCompton Gamma Ray Observatory – this observatory studies X-rays rather than visible light orgamma rays. By capturing images created by these invisible rays, the observatory will allowscientists to analyze some of the greatest mysteries of the universe.

Named in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar, theobservatory was formerly known as the Advance X-ray Astrophysics Facility. The ChandraX-ray Observatory was carried into low Earth orbit by the Space Shuttle Columbia. Theobservatory was deployed from the shuttle’s cargo bay at 155 miles above the Earth. Two firings

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of an attached Inertial Upper Stage rocket and several firings of its own on-board rocket motorsafter separating from the Inertial Upper Stage placed the observatory into its working orbit.

Unlike the Hubble Space Telescope’s circular orbit that is relatively close to the Earth, the ChandraX-ray Observatory was placed in a highly elliptical (oval-shaped) orbit. At its closest approach toEarth, the observatory will be at an altitude of about 6,000 miles. At its farthest, 86,400 miles, ittravels almost one-third of the way to the Moon. Due to this elliptical orbit, the observatory circlesthe Earth every 64 hours, carrying it far outside the belts of radiation that surround our planet.This radiation, while harmless to life on Earth, can overwhelm the observatory’s sensitiveinstruments. The X-ray observatory is outside this radiation long enough to take 55 hours ofuninterrupted observations during each orbit. During periods of interference from Earth’s radiationbelts, scientific observations are not taken.

The Chandra X-ray Observatory has three major elements. They are the spacecraft system, thetelescope system and the science instruments.

The Spacecraft System

The spacecraft module contains computers, communication antennas and data recorders totransmit and receive information between the observatory and ground stations. The onboardcomputers and sensors, with ground-based control center assistance, command and control thevehicle and monitor its health during its expected five-year lifetime.

The spacecraft module also provides rocket propulsion to move and aim the entire observatory,an aspect camera that tells the observatory its position relative to the stars, and a Sun sensorthat protects it from excessive light. Electrical power is provided by solar arrays that also chargethree nickel-hydrogen batteries that provide backup power.

The Telescope System

At the heart of the telescope system is the High-Resolution Mirror Assembly. Since high-energyX-rays would penetrate a normal mirror, special cylindrical mirrors were created. The two sets offour nested mirrors resemble tubes within tubes. Incoming X-rays graze off the highly polishedmirror surfaces and are funneled to the instrument section for detection and study.

The mirrors of the X-ray observatory are the largest of their kind and the smoothest ever created.If the surface of the state of Colorado were as relatively smooth, Pike’s Peak would be less thanone inch tall. The largest of the eight mirrors is almost 4 feet in diameter and 3 feet long.Assembled, the mirror group weighs more than 1 ton.

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The High-Resolution Mirror Assembly is contained in the cylindrical "telescope" portion of theobservatory. The entire length of the telescope is covered with reflective multi-layer insulation thatassists heating elements inside the unit in keeping a constant internal temperature. By maintaining aprecise temperature, the mirrors within the telescope are not subjected to expansion andcontraction – thus ensuring greater accuracy in observations.

The assembled mirrors were tested at NASA’s Marshall Space Flight Center in Huntsville, Ala.Marshall’s world-class X-ray Calibration Facility verified the mirrors’ exceptional accuracy –comparable to the accuracy required to hit a hole-in-one from Los Angeles to San Diego. Thisachievement allows the observatory to detect objects separated by one-half arc second. This iscomparable to reading the letters of a stop sign 12 miles away.

The Chandra X-ray Observatory represents a scientific leap in ability over previous X-rayobservatories like NASA’s Einstein, which orbited the Earth from 1978 to 1981. With its combinationof large mirror area, accurate alignment and efficient X-ray detectors, the Chandra X-rayObservatory has eight times greater resolution and is 20-to-50 times more sensitive than anyprevious X-ray telescope.

Science Instruments

Within the instrument section of the observatory, two instruments at the narrow end of thetelescope cylinder will collect X-rays and study them in various ways. Each of the instruments canserve as an imager or spectrometer.

A High-Resolution Camera will record X-ray images, giving scientists an unequaled look at violent,high-temperature occurrences like the death of stars or colliding galaxies. The High-ResolutionCamera is composed of two clusters of 69 million tiny lead-oxide glass tubes. The tubes are onlyone-twentieth of an inch long and just one-eighth the thickness of a human hair. When X-rays strikethe tubes, particles called electrons are released. As the electrons are accelerated down the tubesby high voltage, they cause an avalanche of about 30 million more electrons. A grid of electricallycharged wires at the end of the tube detects this flood of particles and allows the position of theoriginal X-ray to be precisely determined. The High-Resolution Camera also complements theCharge-Coupled Device Imaging Spectrometer, described below.

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The Chandra X-ray Observatory’s Imaging Spectrometer is also located at the narrow end of theobservatory. This detector is capable of recording not only the position, but also the color (energy)of the X-rays. The imaging spectrometer is made up of 10 charge-coupled device arrays. Thesedetectors are similar to those used in home video recorders and digital cameras but are designed todetect X-rays. Commands from the ground allow astronomers to select which of the variousdetectors to use. The imaging spectrometer can distinguish up to 50 different energies within therange the observatory operates. In order to gain even more energy information, two screen-likeinstruments, called diffraction gratings, can be inserted into the path of the X-rays between thetelescope and the detectors. The gratings change the path of the X-ray depending on its color(energy) and the X-ray cameras record the color and position. One grating concentrates on thehigher and medium energies and uses the imaging spectrometer as a detector – the other gratingdisperses low energies and is used in conjunction with the High Resolution Camera.

By studying these X-ray rainbows, or spectra, and recognizing signatures of known elements,scientists can determine the composition of the X-ray producing objects, and learn how the X-raysare produced.

Observatory Operations

The Smithsonian Astrophysical Observatory controls science and flight operations of the ChandraX-ray Observatory for NASA from Cambridge, Mass. The Smithsonian manages two electronicallylinked facilities – the Operations Control Center and the Science Center.

The Operations Control Center is responsible for directing the observatory’s mission as it orbitsEarth. A control center team interacts with the observatory three times a day – receiving scienceand housekeeping information from its recorders. The control center team also sends newinstructions to the observatory as needed, as well as transmit scientific information from the X-rayobservatory to the Science Center.

The Science Center is an important resource for scientists who wish to study X-ray emittingcelestial objects like quasars and colliding galaxies. The Science Center will provide user support toresearchers, including science data processing and a science data archive. The Science Centerwill work with NASA and the scientific community to allow public access to the scientific results.

NASA and Partners

The Chandra X-ray Observatory program is managed by the Marshall Center for the Office ofSpace Science, NASA Headquarters, Washington, D.C. TRW Space and Electronics Group ofRedondo Beach, Calif., is the prime contractor and has assembled and tested the observatory forNASA. Using glass purchased from Schott Glaswerke, Mainz, Germany, the telescope’s mirrorswere built by Raytheon Optical Systems Inc., Danbury, Conn. The mirrors were coated by OpticalCoating Laboratory, Inc., Santa Rosa, Calif., and assembled by Eastman Kodak Co., Rochester, N.Y.

The Chandra X-ray Observatory Charge-Coupled Device Imaging Spectrometer was developed byPennsylvania State University, University Park, Pa., and the Massachusetts Institute of Technology(MIT), Cambridge. One diffraction grating was developed by MIT, the other by the Space ResearchOrganization Netherlands, Utrecht, Netherlands, in collaboration with the Max Planck Institute,Garching, Germany. The High Resolution Camera was built by the Smithsonian AstrophysicalObservatory. Ball Aerospace & Technologies Corporation of Boulder, Colo., developed the aspectcamera and the Science Instrument Module.

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Chandra X-ray Observatory Technical Details

Size 45.3 feet long x 64.0 feet wide (solar arrays deployed)

Weight 10,560 pounds

Life Minimum 5 years

Orbit 6,000 x 86,400 miles, 64-hour period per orbit

Power Two 3-panel, silicon solar arrays (2,350 watts). Three40-amp-hour nickel-hydrogen batteries for power in eclipse

Data recording Solid-state recorder; 1.8 gigabits (16.8 hours) of recordingcapability

High-Resolution MirrorAssembly

4 sets of nested, grazing incidence paraboloid/hyperboloid mirrorpairs, constructed of Zerodur material- Weight of assembly: 2,104 pounds- Focal length: 10 meters (about 33 feet)- Outer diameter: 1.2 meters (about 4 feet)

Charge-coupled ImagingSpectrometer

Ten charge-coupled device arrays provide simultaneous imagingand spectroscopy

High-Resolution Camera Micro-channel plates detect X-ray photons

Transmission Gratings One high/medium- and one low-energy, gold grating

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Marshall Space Flight Center Fact Sheet

Quick Facts: The Chandra X-ray Observatory

NASA’s newest space telescope, the Chandra X-ray Observatory, will allow scientists fromaround the world to obtain unprecedented X-ray images and spectra of violent, high-temperatureevents and objects to help us better understand the structure and evolution of our universe.

It will also serve as a unique tool to study detailed physics in a unique laboratory -- the universeitself – one that cannot be replicated here on Earth.

Managed by NASA’s Marshall Space Flight Center in Huntsville, Ala., Chandra is a sophisticated,state-of-the-art instrument that represents a tremendous technological advance in X-rayastronomy.

Did you know?

The Chandra X-ray Observatory is the world’s most powerful X-ray telescope. It haseight-times greater resolution and will be able to detect sources more than 20-times fainterthan any previous X-ray telescope. The Chandra X-ray Observatory, with its Inertial Upper Stage and support equipment, is

the largest and heaviest payload ever launched by the Space Shuttle. The Chandra X-ray Observatory’s operating orbit takes it 200-times higher than the HubbleSpace Telescope. During each orbit of the Earth, Chandra travels one-third of the way tothe Moon. The Chandra X-ray Observatory’s resolving power is – 0.5 arc-seconds -- equal to theability to read the letters of a stop sign at a distance of 12 miles. Put another way,Chandra’s resolving power is equivalent to the ability to read a 1-centimeter newspaperheadline at the distance of a half-mile. If the State of Colorado were as smooth as the surface of the Chandra X-ray Observatory

mirrors, Pike’s Peak would be less than an inch tall. Another of NASA’s incredible time machines, the Chandra X-ray Observatory will be able

to study some quasars as they were 10 billion years ago. The Chandra X-ray Observatory will observe X-rays from clouds of gas so vast that it

takes light more than five-million years to go from one side to the other. Although nothing can escape the incredible gravity of a black hole, not even light, theChandra X-ray Observatory will be able to study particles up to the last millisecond beforethey are sucked inside. It took almost four centuries to advance from Galileo’s first telescope to NASA’s HubbleSpace Telescope — an increase in observing power of about a half-billion times. NASA’sChandra X-ray Observatory is about one-billion times more powerful than the first X-raytelescope, and we have made that leap in slightly more than three decades.

Chandra Mission at a Glance:

Chandra X-ray Observatory Mission Duration

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Chandra science mission Approx. 5 yrs

Orbital Activation & Checkout period Approx. 2 mos

Orbital Data

Inclination 28.5 degrees

Altitude at apogee 86,487 sm

Altitude at perigee 5,999 sm

Orbital period 64 hrs

Observing time per orbital period Up to 55 hrs

Dimensions

Length – (Sun shade open) 45.3’

Length – (Sun shade closed 38.7’

Width – (Solar arrays deployed) 64.0’

Width – (Solar arrays stowed) 14.0’

Weights

Dry 10,560 lbs

Propellant 2,153 lbs

Pressurant 10 lbs

Total at launch 12,930 lbs

Integral Propulsion System

Liquid Apogee Engines 4 engines

(Only 2 used at a time)

Fuel Hydrazine

Oxidizer Nitrogen tetroxide

Thrust per engine 105 lbs

Electrical Power

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Solar Arrays 2 arrays

3 panels each

Power generated 2,350 watts

Electrical power storage 3 batteries

40-amp-hour

nickel hydrogen

Communications

Antennas 2 low-gain antennas

Communication links Shuttle Payload Interrogator

Deep Space Network

Command link 2 kbs per second

Data downlink 32 kbs to 1024 kbs

On-board Data Capture

Method Solid-state recorder

Capacity 1.8 gbs

16.8 hrs

High Resolution Mirror Assembly

Configuration 4 sets of nested,

grazing incidence

paraboloid/hyperboloid

mirror pairs

Mirror Weight 2,093 lbs

Focal length 33 ft

Outer diameter 4 ft

Length 33.5 in

Material Zerodur

Coating 600 angstroms of iridium

Attitude Control & Pointing

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Reaction wheels 6

Inertial reference units 2

Aspect camera 1.40 deg x 1.40 deg fov

Science Instruments

Charged Coupled Imaging Spectrometer (ACIS)

High Resolution Camera (HRC)

High Energy Transmission Grating (HETG)

Low Energy Transmission Grating (LETG)

The Inertial Upper Stage

Dimensions

Length 17.0’

Diameter 9.25’

Weights

Stage 1 – Dry 2,566 lbs

Stage 1 – Propellant 19,621 lbs

Stage 1 - Total 22,187 lbs

Stage 2 – Dry 2,379 lbs

Stage 2 – Propellant 6,016 lbs

Stage 2 - Total 8,395 lbs

Total Inertial Upper Stage – At launch 30,582 lbs

Performance

Thrust – Stage 1 46,198 lbs, average

Burn Duration – Stage 1 125 seconds

Thrust – Stage 2 16,350 lbs, average

Burn Duration – Stage 2 117 seconds

Support Equipment

Weights

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Airborne Support Equipment 5,365 lbs

Other 1,285 lbs

Total Support Equipment 6,650 lbs

Total Payload

Weight

Total Chandra/IUS/Support

equipment at liftoff

50,162 lbs

Length

Total IUS/Chandra 57.0’

Biographies

DR. ROBERT KIRSHNERASSOCIATE DIRECTOR, HARVARD-SMITHSONIAN CENTER FOR ASTROPHYSICS

Robert Kirshner is Professor of Astronomy at HarvardUniversity and an Associate Director of the Harvard-Smithsonian Center for Astrophysics. He graduatedfrom Harvard College in 1970 and received a Ph.D. inastronomy at Caltech four years later. After a postdocat Kitt Peak National Observatory in Tucson, he joinedthe faculty at the University of Michigan for 9 yearsbefore moving to the Harvard Astronomy Departmentin 1986. He served as Chairman of the departmentfrom 1990-1997.

Professor Kirshner is an author of 200 researchpapers dealing with supernovae, the large-scale distribution of galaxies, and the sizeand shape of the Universe. His recent work on the acceleration of the Universe wasdubbed the "Science Breakthrough of the Year for 1998" by Science Magazine. Anarticle by Kirshner and his collaborators on this topic appears in the January 1999Scientific American. He was elected to the National Academy of Sciences in 1998.

Kirshner is a frequent public lecturer on science, including the 1997 Princeton Universitylectures, the 1998 Seyfert Lecture at Vanderbilt University, and a featured talk to theNational Science Teachers Association at their national meeting in 1999. He is also theteacher of Science A-35, a core curriculum course for 250 Harvard undergraduatesentitled "Matter in the Universe." The vivid (and slightly hazardous) demonstrations inScience A-35 led to Kirshner's being featured in Boston Magazine in their October 1998article on "Nutty Professors". Kirshner has made a series of video tapes on "CosmicQuestions" for The Teaching Company which are widely available.

Biographies

DR. HARVEY TANANBAUMDIRECTOR, CHANDRA X-RAY CENTER

Dr. Harvey Tananbaum is director of the SmithsonianAstrophysical Observatory's Chandra X-ray Center(CXC). In this capacity he is responsible for overseeingthe operation of the Chandra X-ray Observatory andproviding support to the scientificusers of the observatory.

Tananbaum graduated from Yale University in 1964.After receiving his Ph.D. in physics from MIT in 1968, hejoined American Science & Engineering where hebecame project scientist for NASA's Uhuru X-ray Satellite. In 1973 he moved to theHarvard-Smithsonian Center for Astrophysics. The launch and operation of the ChandraObservatory will be the culmination of a 23 year journey for Tananbaum, who has beeninvolved with the Chandra project from the beginning. In 1976, he and Riccardo Giacconisubmitted a proposal letter to NASA to initiate the study and design of a large x-raytelescope. In 1977, work was begun on the project, which was then known as theAdvanced X-ray Astrophysics Facility (AXAF). In 1998, AXAF was renamed the ChandraX-ray Observatory.

Tananbaum has been working in x-ray astronomy since his graduate days at MIT. Histhesis research was on a mysterious type of cosmic x-ray source. Later, when he wasproject scientist for the Uhuru X-ray Satellite, observations by the satellite wereinstrumental in showing that this source was due to matter falling into a black hole.Tananbaum was the scientific program manager for the Einstein Observatory, the firstlarge imaging x-ray telescope. In 1981 he became Associate Director for High EnergyAstrophysics at the Harvard-Smithsonian Center for Astrophysics, a position he held for12 years. In 1991, he was appointed director of the CXC.

Tananbaum received the NASA Exceptional Scientific Achievement Medal in 1980, andthe NASA Public Service Award in 1988. He is a fellow of the American Association forthe Advancement of Science, and has served as vice-president of the AmericanAstronomical Society, as well as on numerous NASA advisory committees.

Biographies

DR. EDWARD J. WEILERASSOCIATE ADMINSTRATOR FOR SPACE SCIENCE,NASA

In November 1998 Dr. Edward J. Weiler was appointed asNASA's Associate Administrator for Space Science. In thiscapacity, Weiler is responsible for providing overall executiveleadership of NASA's Space Science Enterprise. Thisenterprise aims to achieve a comprehensive understanding ofthe origins and evolution of the Solar System and the Universe,including connections between the Sun and the Earth, thebeginnings of life and the question of whether life existselsewhere beyond Earth. It also is charged with communicatingthis knowledge to the public.

Weiler was appointed as Science Director of the Astronomical Search for Origins andPlanetary Systems theme within the Office of Space Science in March 1996. He willcontinue to serve as the Program Scientist for the Hubble Space Telescope, a positionhe has held since 1979, until a replacement for that position is selected. Weiler joinedNASA in 1978 as a staff scientist.

Prior to that, Weiler was a member of the Princeton University research staff and wasbased at NASA'S Goddard Space Flight Center, Greenbelt, MD, as the director ofscience operations of the Orbiting Astronomical Observatory-3 (COPERNICUS). Weilerreceived his Ph.D. in astrophysics from Northwestern University in January 1976. Hehas published over 20 papers in the scientific journals. Dr. Weiler has receivednumerous awards, including the NASA Outstanding Leadership Medal and the 1994Presidential Rank Award of Meritorious Executive for his work on HST.

Biographies

DR. MARTIN C. WEISSKOPFPROJECT SCIENTIST, CHANDRA X-RAYOBSERVATORY

Dr. Martin C. Weisskopf is Project Scientist for NASA'sChandra X-ray Observatory and Chief Scientist for X-rayAstronomy at NASA's Marshall Space Flight Center inHuntsville, Ala.

NASA's Chandra X-ray Observatory, the world's mostpowerful X-ray telescope, will help scientists understandthe structure and evolution of the universe.

Weisskopf began his post-graduate career at ColumbiaUniversity in 1969, where he became an assistant professor and performed manypioneering experiments in X-ray astronomy including helping to write the proposal forwhat was to become the Einstein Observatory, the forerunner to the Chandra X-rayObservatory. In 1977, Weisskopf left Columbia to become senior X-ray astronomer atMarshall Center and Chandra X-ray Observatory Project Scientist. In this capacity he isresponsible for the scientific integrity of the Chandra X-ray Observatory.

Weisskopf has held numerous special appointments during his career. He is a SeniorCo-investigator of the European Space Agency's international X-ray imaging experiment,called IBIS, and holds a similar position for an experiment to fly on the SPECTRUM-Xmission being developed for X-ray study by the Russian Space Research Institute. He isPrincipal Investigator of a major experimental research program initiated in 1978 thatcurrently concentrates on the development of X-ray optics.

He has served on numerous committees, including the National Academy of Science'sPanel on High-Energy Astrophysics from Space, Astronomy and Astrophysics SurveyCommittee. He is a member of the American Astronomical Society High-EnergyAstrophysics Division; the American Association for the Advancement of Science; theInternational Astronomical Union; Sigma Xi, a scientific research society; Phi BetaKappa, the National Honor Society and a Fellow of the American Physical SocietyAstrophysics Division.

Weisskopf is the recipient of numerous awards, including the NASA Medal forExceptional Service. He is author or co-author of 171 journal articles, books,monographs and papers in conference proceedings.

In 1964, he received his bachelor's degree with honors in physics from Oberlin Collegein Cleveland, Ohio, and in 1969 received his doctorate in physics from BrandeisUniversity in Waltham, Mass.